The present invention relates to the operation of a drive aggregate, or unit, in which a certain fuel is used for combustion under conditions which are independent from the availability of ambient air (oxygen) so that such an aggregate or unit can be particularly used in underwater operation.
Submarines or other underwater vehicles are driven, for example, by electro-engines, or motors or pump-jet drives or on utilization of combustion and/or reaction drives which operate without requiring access to ambient air. For example, German printed patent application No. 24 59 556 discloses a drive for a submarine having a drive turbine which is operated by the catalytic decomposition of hydrazine under utilization of the energy released in a hydrazine-water mixture. Drives of this type are particularly conceived for use in torpedoes and, depending upon design and power, sufficient operating periods and, particularly, operating range for a torpedo can be obtained.
It is inevitable in such a drive that bubbles develop. On the other hand, a successful utilization of torpedoes requires that bubbles are not developed. Therefore, it has been suggested specifically to pump back those gasses which will not go into solution completely in water, under utilization of the compressor whereby, particularly, these gasses will be returned to the hydrazine container.
Aside from the hydrazine-type drive aggregates which do not require external air for the reaction, it is also known to use a solid fuel, for example, lithium aluminum hydride or metals which react with water in a chamber so as to obtain a reaction which yields a sufficient amount of energy. German Printed Patent Application No. 21 27 046 discloses by way of example a particular solid fuel for a drive, but this particular fuel is disadvantaged by a spontaneous reaction capability with water and other oxidizers. Moreover, this particular kind of solid fuel is very difficult to transport and most certainly cannot be pumped, so that the control of such a drive aggregate, as far as the fuel is concerned, depends exclusively on the controlability of the oxidizer.